Prospective evaluation of the RT-PCR based urinary marker Bladder Epicheck® as a diagnostic tool in upper urinary tract tumor.

Background: Upper-tract-urothelial-carcinoma (UTUC) represents 5-10% of all urothelial-neoplasms with increasing incidence in the last decades. Current standard tools for diagnosis of UTUC include cytology, computed tomography (CT) urography and ureterorenoscopy (URS). The aim of this study was to evaluate the impact of Bladder Epicheck Test as diagnostic tool for UTUC diagnosis and recurrence.

Methods: Overall, 136 urine samples, selective collected from upper-urinary-tract before URS for suspicion of UTUC were analyzed with cytology and Bladder Epicheck Test. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of both markers were calculated and compared to URS and/or histology as reference.

Results: UTUC was detected in 40 cases (33.3%), among them 30 were classified as low-grade (LG) and 10 as high-grade (HG). Overall sensitivity of Bladder Epicheck for UTUC detection was 65% compared to 42.5% for cytology, increasing to 100% for Bladder Epicheck and 90% for cytology if considering only HG tumors. Overall specificity of Bladder Epicheck was 81.2% and of cytology 93.7%. PPV and NPV were 63.4% and 82.2% for Bladder Epicheck and 77.2% and 76.5% for cytology. Considering an EpiScore cut-off >75, instead of 60, specificity of Bladder Epicheck improves to 89% and PPV to 74.2%. Limitations include the use of a marker validated only for bladder-cancer and the relatively small number of cases.

Conclusions: Due to its high sensitivity for HG tumors, the Bladder Epicheck Test can be used in diagnosis and treatment decision-making of UTUC. Furthermore, it could be very useful in follow-up of UTUC, after endoscopic treatment to postpone or avoid unnecessary endoscopic exploration. Even if further studies are needed to validate these findings, Bladder Epicheck could be a promising clinical tool for detection of UTUC.